package resources

import (
	"context"
	"fmt"

	"github.com/hashicorp/terraform-plugin-framework/resource"
	"github.com/hashicorp/terraform-plugin-framework/resource/schema"
	"github.com/hashicorp/terraform-plugin-framework/resource/schema/planmodifier"
	"github.com/hashicorp/terraform-plugin-framework/resource/schema/stringplanmodifier"
	"github.com/hashicorp/terraform-plugin-framework/types"
	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"

	"terraform-provider-fission/internal/client"
)

var _ resource.Resource = &CronTriggerResource{}

// CronTriggerResource управляет Fission TimeTrigger (CRON).
type CronTriggerResource struct {
	client *client.Client
}

type cronTriggerResourceModel struct {
	ID        types.String `tfsdk:"id"`
	Name      types.String `tfsdk:"name"`
	Namespace types.String `tfsdk:"namespace"`
	Function  types.String `tfsdk:"function"`
	Cron      types.String `tfsdk:"cron"`
	UID       types.String `tfsdk:"uid"`
}

func NewCronTriggerResource() resource.Resource {
	return &CronTriggerResource{}
}

func (r *CronTriggerResource) Metadata(_ context.Context, req resource.MetadataRequest, resp *resource.MetadataResponse) {
	resp.TypeName = req.ProviderTypeName + "_cron_trigger"
}

func (r *CronTriggerResource) Schema(_ context.Context, _ resource.SchemaRequest, resp *resource.SchemaResponse) {
	resp.Schema = schema.Schema{
		Description: "Fission TimeTrigger — запускает функцию по CRON-расписанию.",
		Attributes: map[string]schema.Attribute{
			"id": schema.StringAttribute{
				Computed:    true,
				Description: "Идентификатор ресурса (namespace/name).",
			},
			"name": schema.StringAttribute{
				Required:    true,
				Description: "Имя TimeTrigger.",
				PlanModifiers: []planmodifier.String{
					stringplanmodifier.RequiresReplace(),
				},
			},
			"namespace": schema.StringAttribute{
				Optional:    true,
				Computed:    true,
				Description: "Kubernetes namespace.",
				PlanModifiers: []planmodifier.String{
					stringplanmodifier.RequiresReplace(),
				},
			},
			"function": schema.StringAttribute{
				Required:    true,
				Description: "Имя Fission Function для запуска.",
			},
			"cron": schema.StringAttribute{
				Required:    true,
				Description: "CRON-расписание, например \"*/10 * * * *\".",
			},
			"uid": schema.StringAttribute{
				Computed:    true,
				Description: "UID объекта в Kubernetes.",
			},
		},
	}
}

func (r *CronTriggerResource) Configure(_ context.Context, req resource.ConfigureRequest, resp *resource.ConfigureResponse) {
	if req.ProviderData == nil {
		return
	}
	c, ok := req.ProviderData.(*client.Client)
	if !ok {
		resp.Diagnostics.AddError("Неверный тип провайдера", fmt.Sprintf("ожидался *client.Client, получен %T", req.ProviderData))
		return
	}
	r.client = c
}

func (r *CronTriggerResource) Create(ctx context.Context, req resource.CreateRequest, resp *resource.CreateResponse) {
	var plan cronTriggerResourceModel
	resp.Diagnostics.Append(req.Plan.Get(ctx, &plan)...)
	if resp.Diagnostics.HasError() {
		return
	}

	ns := plan.Namespace.ValueString()
	if ns == "" {
		ns = r.client.Namespace
	}

	obj := buildTimeTrigger(plan.Name.ValueString(), ns, plan.Function.ValueString(), plan.Cron.ValueString())
	created, err := r.client.CreateTimeTrigger(ctx, obj)
	if err != nil {
		resp.Diagnostics.AddError("Ошибка создания CRON trigger", err.Error())
		return
	}

	plan.ID = types.StringValue(ns + "/" + plan.Name.ValueString())
	plan.Namespace = types.StringValue(ns)
	plan.UID = types.StringValue(string(created.GetUID()))
	resp.Diagnostics.Append(resp.State.Set(ctx, &plan)...)
}

func (r *CronTriggerResource) Read(ctx context.Context, req resource.ReadRequest, resp *resource.ReadResponse) {
	var state cronTriggerResourceModel
	resp.Diagnostics.Append(req.State.Get(ctx, &state)...)
	if resp.Diagnostics.HasError() {
		return
	}

	obj, err := r.client.GetTimeTrigger(ctx, state.Namespace.ValueString(), state.Name.ValueString())
	if err != nil {
		if client.IsNotFound(err) {
			resp.State.RemoveResource(ctx)
			return
		}
		resp.Diagnostics.AddError("Ошибка чтения CRON trigger", err.Error())
		return
	}

	spec, _, _ := unstructured.NestedMap(obj.Object, "spec")
	if cron, ok := spec["cron"].(string); ok {
		state.Cron = types.StringValue(cron)
	}
	if fnRef, ok := spec["functionref"].(map[string]any); ok {
		if name, ok := fnRef["name"].(string); ok {
			state.Function = types.StringValue(name)
		}
	}
	state.UID = types.StringValue(string(obj.GetUID()))
	resp.Diagnostics.Append(resp.State.Set(ctx, &state)...)
}

func (r *CronTriggerResource) Update(ctx context.Context, req resource.UpdateRequest, resp *resource.UpdateResponse) {
	var plan cronTriggerResourceModel
	resp.Diagnostics.Append(req.Plan.Get(ctx, &plan)...)
	if resp.Diagnostics.HasError() {
		return
	}

	existing, err := r.client.GetTimeTrigger(ctx, plan.Namespace.ValueString(), plan.Name.ValueString())
	if err != nil {
		resp.Diagnostics.AddError("Ошибка получения CRON trigger для обновления", err.Error())
		return
	}

	if err := unstructured.SetNestedField(existing.Object, plan.Cron.ValueString(), "spec", "cron"); err != nil {
		resp.Diagnostics.AddError("Ошибка обновления cron", err.Error())
		return
	}
	if err := unstructured.SetNestedField(existing.Object, plan.Function.ValueString(), "spec", "functionref", "name"); err != nil {
		resp.Diagnostics.AddError("Ошибка обновления function", err.Error())
		return
	}

	updated, err := r.client.UpdateTimeTrigger(ctx, existing)
	if err != nil {
		resp.Diagnostics.AddError("Ошибка обновления CRON trigger", err.Error())
		return
	}

	plan.UID = types.StringValue(string(updated.GetUID()))
	resp.Diagnostics.Append(resp.State.Set(ctx, &plan)...)
}

func (r *CronTriggerResource) Delete(ctx context.Context, req resource.DeleteRequest, resp *resource.DeleteResponse) {
	var state cronTriggerResourceModel
	resp.Diagnostics.Append(req.State.Get(ctx, &state)...)
	if resp.Diagnostics.HasError() {
		return
	}
	if err := r.client.DeleteTimeTrigger(ctx, state.Namespace.ValueString(), state.Name.ValueString()); err != nil {
		resp.Diagnostics.AddError("Ошибка удаления CRON trigger", err.Error())
	}
}

func buildTimeTrigger(name, ns, functionName, cron string) *unstructured.Unstructured {
	return &unstructured.Unstructured{
		Object: map[string]any{
			"apiVersion": "fission.io/v1",
			"kind":       "TimeTrigger",
			"metadata": map[string]any{
				"name":      name,
				"namespace": ns,
			},
			"spec": map[string]any{
				"cron": cron,
				"functionref": map[string]any{
					"type": "name",
					"name": functionName,
				},
			},
		},
	}
}